Extreme moisture in crawl space

[Ben H]

Need a little advice from a greybeard or two[]. The crawl in todays house had a VERY large around of moisture, but not on the ground. It was hanging from duct work and insulation. It did not smell musty either...

The crawl was indeed not vented well, but in my mind something else has to be going on. I'd say roughly 75% of the insulation had water drops hanging from it. There was a little water here and there on the VB, but not what I could call a lot. Not really standing water, just a teaspoon here and there...

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[Jim Katen]

Where was the dryer vent?

- Jim Katen, Oregon

[John Kogel]

Are they pumping ice cold air thru their ducts? I believe damp air is trapped in the crawlspace, then moisture is precipitating out of the damp air onto a cooler surface.

There could be a leaking duct from a clothes dryer down there. I'd check for that. Jim, you beat me to it!

I would install at least two vents and put a fan on one of them.

That is not something I'd ever see in my climate, so in the end, I don't have a clue. []

[Ben H]

Jim: Dryer vent is OK.

John: Crazy right? There are a few vents in the crawl, but this house is 3600sf, mostly on 1st floor. Pretty good size footprint.

What or who would you guys punt this to? Foundation guy? Insulation guy? Both? []

[David Meiland]

Is the a/c on and running thru those ducts? What was the temp/RH/dewpoint in the crawl?

Absent a dryer vent leak or some other egregious source of warm moist air, the answer may be that the ducts need to be sealed with mastic, and probably insulated, and sources of moisture need to be controlled (how good was the ground cover, any observations on drainage around the perimeter?)

[Ben H]

Hey David, yeah they are running A/C through those lines. The crawl was very cool in temp vs the house/outside. I didn't find any leaking A/C vents, but there could have been some.

Ground cover was actually pretty good, typical heavy mil plastic laid out. Not the greatest around the edge, but over all not bad.

I just can't get over the amount of moisture, by far the most I've ever seen.

[hausdok]

Vapor diffusion,

In some parts of the country crawlspace ventilation is a balancing act. In colder months you have to have plenty of vents open and air movement through the crawl to help dispel moisture buildup under the home as the humidity under the home bypasses the exterior humidity and spikes; in the warmer summer months when the humidity outside spikes you have to find a way to keep the crawl at around the same temperature/humidity as outside or you'll create your rain forest.

Vapor diffusion is the process of air moving from moister to drier and from warmer to cooler. If exterior humidity in Kentucky right now is higher than what you have in the crawl, and if the interior of the home is air conditioned and the floor of the home is coolest (warm air falls, warmer air rises so the floor should be the coolest place in the home), you have warm air diving in there seeking that cold dry area under the floors. I'm guessing that the insulation isn't snug against the underside of the floor above and warm/moist exterior air is migrating into the cool place above that insulation where it's condensing to water and then drips back down through the insulation.

Tell them to get a building scientist in to design a system that will keep interior crawlspace air balanced with exterior air. Check out advancedenergy.org.

ONE TEAM - ONE FIGHT!!!

Mike

[Bain]

Despite his proclivity for girly language, Ben, Mike is spot-on lots of times. This is one of those times. I'm 75 miles east of you, and I see what you're describing fairly often. It's been wicked humid lately, which has exacerbated what's happening in the house you looked at today.

I don't know about Louisville, but there aren't any building scientists readily available in Lexington. Here, there's a waterproofing contractor who is really adept at conquering problems like the one in your house.

If this sounds patronizing, please forgive me--But never make recommendations for correcting these kinds of problems. An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

[Ben H]

Despite his proclivity for girly language, Ben, Mike is spot-on lots of times. This is one of those times. I'm 75 miles east of you, and I see what you're describing fairly often. It's been wicked humid lately, which has exacerbated what's happening in the house you looked at today.

I don't know about Louisville, but there aren't any building scientists readily available in Lexington. Here, there's a waterproofing contractor who is really adept at conquering problems like the one in your house.

If this sounds patronizing, please forgive me--But never make recommendations for correcting these kinds of problems. An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Thanks guys. No worries Bain, I know when I'm "above my knowledge" with a problem and this is one of those times. [:-graduat

Seems like some fancy dancy report writing is at hand.

[hausdok]

An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Now, that's home inspector news. Any way to wangle a home inspector article out of that? Links?

ONE TEAM - ONE FIGHT!!!

Mike

[Scottpat]

If this sounds patronizing, please forgive me--But never make recommendations for correcting these kinds of problems. An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Any more information on that case? City, etc..??

That is one of the highest if not the highest against a home inspector. I would love to read more about it.

[Scottpat]

Are they pumping ice cold air thru their ducts? I believe damp air is trapped in the crawlspace, then moisture is precipitating out of the damp air onto a cooler surface.

There could be a leaking duct from a clothes dryer down there. I'd check for that. Jim, you beat me to it!

I would install at least two vents and put a fan on one of them.

That is not something I'd ever see in my climate, so in the end, I don't have a clue. []

One misnomer is adding a fan in a crawlspace to blow air out of it. You really do not want to do this for a couple reasons.

1. You will be blowing air out but in turn you will also be sucking in warmer and possibly even more humid air. You have just compounded the problem with the fan.

2. You can actually depressurize the home. Another problem all in it's self.

[Bain]

An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Now, that's home inspector news. Any way to wangle a home inspector article out of that? Links?

ONE TEAM - ONE FIGHT!!!

Mike

It was personally and professionally devastating for the person involved, and I don't think it's appropriate to compound his misfortune by splashing details on the internet.

[kurt]

Well, I'm curious too......I've often nightmared on this topic......

Is the guy a screwup type? Did he get caught in an unforeseen cataclysm?

[hausdok]

An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Now, that's home inspector news. Any way to wangle a home inspector article out of that? Links?

ONE TEAM - ONE FIGHT!!!

Mike

It was personally and professionally devastating for the person involved, and I don't think it's appropriate to compound his misfortune by splashing details on the internet.

I'm absolutely certain that it was; I'm also absolutely certain that other home inspectors can learn something from it that might keep more than a few of them from making similar mistakes.

ONE TEAM - ONE FIGHT!!!

Mike

[Scottpat]

An inspector in another part of our state was sued and socked with a 3 million dollar judgment in the recent past because of moisture and mold issues.

Now, that's home inspector news. Any way to wangle a home inspector article out of that? Links?

ONE TEAM - ONE FIGHT!!!

Mike

It was personally and professionally devastating for the person involved, and I don't think it's appropriate to compound his misfortune by splashing details on the internet.

Well, if it is a judgement then it is public information and it is available for folks to see. Now if it was a settlement then it is not so public. I can't imagine a settlement of that size.

I'm sure that nobody wants to wish this on anyone but we need to look at lawsuits as learning tools. Every single case that I work on as an EW, I learn somthing new. Either in regards to what not to do, about a situation, building product, about construction and on and on. Our profession is a new experience every single day we work.